Egg sex experiment

[eLiV8t]

Has anyone tried to pick out certain eggs in order to get more or only pullets (hens or females)?
I'm testing this out.
I pulled out the eggs that looked pointed and kept the roundest eggs under my broody hen.
They started hatching yesterday and I hope this experiment works. Have you tried this?
How did it turn out?

 

[eLiV8t]

 

[nuthatched]

There was someone who did this a few weeks ago.
The shape of egg thing is a old wives tale. What the egg is, is actually what we call the yolk, the shape of the shell that encapsulates the yolk has everything to do with to state of the individual hens reproductive tract and none with the gender of the yolk.

 

[UrbanHomesteadTX]

Adorable babies! My experience and understanding comes down to the whole round egg thing being nothing more than an old wives tale.
My girls each lay a specific shape that is directly tied to them. One hen always lays extra large fairly round eggs, another always lays very long pointed eggs. I always know which egg belongs to which hen strictly based off of shape, even though they're all perfectly white.
The long pointed eggs hatch just as many hens and roosters as the large rounded eggs do.

Nevertheless, people still have fun experimenting with this method, I say have fun with the attempt! But I wouldn't bet on it being a sure thing. Do let us know how many hens you get though!

 

[eLiV8t]

Hi, I found this information onhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC9832119/#:~:text=In%20general%2C%20eggs%20with%20a,1.&text=Oval%20shape%20egg%20for%20female,for%20male%20chicks%20(right).


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Sci Rep. 2023; 13: 504.
Published online 2023 Jan 10. doi: 10.1038/s41598-023-27772-4
PMCID: PMC9832119
PMID: 36627389

High accuracy gender determination using the egg shape index​

Muhammed Kayadan and Yunus Uzun

Author information Article notes Copyright and License information PMC Disclaimer

Associated Data​

Data Availability Statement

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Abstract​

Since only female chicks are used in layer hens, usually hatched male chicks are killed. It is estimated that around 7 billion chicks per year are killed immediately after hatching. In addition to being unethical, this situation also causes great financial losses. Sex determination in chicks can be done before or after hatching. Of course, determinations made before hatching are more advantageous, but the prediction rate is relatively low. The morphology of an egg is expressed in terms of the Shape Index (SI), which is the ratio of the short diameter to the long diameter. In this study, male and female chicks were predicted by using the shape index of the eggs using the RUSBoost Classifier using Shape Index. Although SI varied according to the egg type, a significant correlation (r = 0.78) was observed between chick sex and SI. Therefore, it was possible to estimate gender by utilizing SI in chickens, even if the accuracy of classification was not as high as in ducks. Besides the SI, mass, short axis, long axis, ovality, volume, eccentricity parameters were obtained and used for the results. With this features, females classified with 80% and males classified 81% correctly. The model predictions were applied to the probability of female chick hatching equation from the previous studies, 71% of the estimations were correctly classified according to this equation.With this work, around 80% of accurate predictions were made. In this case, killing 5.65 billion chicks can be prevented. Likewise, many eggs are not wasted. 1.13 billion USD loss can be prevented.
Subject terms: Electrical and electronic engineering, Computational science

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Introduction​

Feeding and breeding activities are carried out to provide the necessary nutrients to the rapidly growing world population. The egg sector is one of the main sectors in the world. To increase egg production, breeding studies are carried out and studies on the chickens are continuing. Due to efficiency reasons, broiler and layer species have been selected for breeding by different features. Broilers grow fast and become ready to cut in short time. In the other hand, layers do not grow that fast and will not be heavy when they develop. Male and female numbers of chicken eggs are close to each other1. The presence of male chicks in the egg sector is a major problem. They do not make eggs, nor do they make a profit when they are grown and sold for slaughter. Therefore, male chicks are selected by the sexers and are culled unethically using different methods such as slaughter, gas strangulation, or strangulation in an oxygen-free environment when they have just hatched. A minority are painted and sold in pet shops2.
Assuming that the male chicks are not separated, they will consume a lot of feed up to slaughter and the income received after slaughter will be much less than the expense. A rooster eats an average of one hundred grams of feed per day. In a farm which has 100 K chickens, in case the roosters are not separated, 100 K roosters will take place in the farm. Only the daily feed mass of the roosters will be 10 K kg. Considering that roosters eat a feed with a price of 1 USD per kilogram, 10 K USD per day means that only the feed money will go for the roosters. On the other hand, the kilogram price of their meat will be a maximum of 2 USD and it will be 2 kg when they develop. If there is no waste at the end of the 6-month average feed consumption, 2 USD * 2 kg * 100 K Pieces = 400 K USD income will be obtained. In contrast, 10 K USD * 6 Months * 30 Days = 1800 K USD expense. In this case, there is a loss of 1.400 K USD.
The number of birds per unit area is decisive on their health and profitability3. There should be 6–7 chickens per square meter4. Approximately 15,500 m2 of extra space is required for 100 K roosters. If it is calculated that 100 K roosters hatch from all eggs without wastage, 100 K eggs are hatched. Assuming an average egg is 0.2 USD, it means a loss of 20 K USD because of egg expenses. 7 billion male chicks are culled annually in the world2. This is a loss of 1.4 billion USD. In addition to all these, economic losses will occur in many items such as the use of extra incubators, extra electrical energy spent for the incubator, and the number of personnel to work.
In the hatchery, the sexers separate chicks into male and female. In the egg sector, because only the female chickens are useful, it is necessary to separate them. Chick sex can be determined in three different stages. These are sex determination before incubation, during incubation, and after incubation. In this work, sex determination before incubation is used because this is the most useful method to save the life of the chick inside or hatched eggs and to prevent the waste of eggs.
It is possible to determine the gender with great accuracy before the eggs are incubated, and the most determinant measure in this method is the egg shape index5–10. In7, 300 White Nick Super Layer eggs were examined with an unsupervised regression method, and female hatching probability was suggested. In8, 340 Pekin duck eggs were studied, and 0.71 positive correlation coefficient was found. In9, 103 duck eggs were examined and 86% accuracy was obtained. In10, 503 duck eggs were used with different machine learning algorithms and 87% accuracy was obtained. There are some different techniques, such as the use of fluorescence11,12, Raman spectroscopy13, egg shape index8, DNA glycosylase14, to detect sex of the chicks. Except for the morphological methods, all the methods need complicated, expensive tools and the eggs were perforated. In-ovo egg sexing methods are applicable only during the incubation, therefore male eggs are getting wasted. The shape index method can be applicable before incubation; thus male eggs can be sold to the market for daily consumption. Furthermore, the earliest period of in-ovo methods is the ninth day of the incubation; hence, sources will still be used, and alive-in-egg chicks will be culled. There is a need for an industry-applicable, reliable, fast-working method on chicken breeds. Because of these reasons, industrial in-ovo selection devices are still not fully applicable in the poultry industry. The studies which it used the shape index method are mostly on ducks, but duck egg models cannot be applied to chicken eggs because of their different morphology. Dikmen7 suggested a regression analysis, instead of a classification model. We are suggesting our classification model for chicken breeds, which does not harm eggs and is very fast.
In this study, sex determination using the shape index of the egg is preferred since the other methods are both costly and difficult to use in serial analysis. The shape index (SI) is the ratio of the short diameter of the egg to the long diameter15,16. In general, eggs with a low shape index will be male chicks, eggs with a high shape index will be female chicks. In general, eggs are of two types, oval shape and pointed shape, as seen in Fig. 1.

[IMG alt="An external file that holds a picture, illustration, etc.
Object name is 41598_2023_27772_Fig1_HTML.jpg"]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9832119/bin/41598_2023_27772_Fig1_HTML.jpg[/IMG]​

Figure 1
Oval shape egg for female chicks (left) and pointed shape egg for male chicks (right).
The shape index (SI) is the ratio of the short diameter of the egg to the long diameter. When using the egg shape index, the standard deviation of the shape index is quite low. (0.03844 mm in 60 eggs) So sex discrimination is very difficult. Therefore, it was decided to use different methods in comparison. In this way, possible performance comparison was aimed. The results obtained will be compared with the sex of the hatching chicks and the method with the highest accuracy will be determined.
In accordance with all these conditions, the following methods have been decided:

• Sex classification with a supervised learning algorithm. RUSBoosted was used in this study.
• Determine the shape index by directly measuring the short and long axis of the egg, and gender discrimination according to the threshold value.

Specify both eccentricity (automatic SI) and short and long axis shape index (manual SI) using MATLAB Image Processing Toolboxwith this study, the relation between shape index of the eggs and sex of chicks was questioned, and the results were listed.

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Methodology​

The experiment was carried out in the Aksaray University hatcheries in accordance with the national regulations on wellness and protection of animals used for experimental and other scientific purposes. Eggs for the experiment were bought from the local backyard poultry farms. The morphology of an egg varies on the chicken breed and in the local backyard farm had a hybrid flock. Egg images were taken before the incubation. Eggs were clamped down by their long axis and camber alignment tools was used to lay eggs down most accurately. (Mitutoyo 06,389,100, 0.01 mm accuracy) Each egg was given an identical number (from 0 to 60), and their ID number was written on eggs and their corresponding incubation tray cells with a marker. First, 18 days of incubation eggs were arranged in numerical order, however, the last 3 days’ incubator trays were divided into cells for tracking chicks. It is crucial for sex pairing between eggs and chicks in supervised learning. Figure 2 shows the cell structure in the incubation tray. For the tray dividing process, netted materials were obligated to use due to air circulating. After hatching, the chicks were one week old, distinguishing them was done by visual inspection based on their body size, comb color, and feathering.

[IMG alt="An external file that holds a picture, illustration, etc.
Object name is 41598_2023_27772_Fig2_HTML.jpg"]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9832119/bin/41598_2023_27772_Fig2_HTML.jpg[/IMG]​

Figure 2
Divided incubation tray structure.
Mass is scaled with the Diheng THR219 0.01-g sensitive scale and recorded. For the physical measurements, short axis |CD|, long axis |AB|, and the maximum point |AE| (on where bumpy side (C point) touches to calliper) is measured with 0.01 mm sensitive digital calliper. In previous studies, Shape Index (SI) is used7,8,16. The Shape Index is the ratio of the short axis to the long axis and on Fig. 3:

Shapeindex=ShortAxisLongAxis
1​

[IMG alt="An external file that holds a picture, illustration, etc.
Object name is 41598_2023_27772_Fig3_HTML.jpg"]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9832119/bin/41598_2023_27772_Fig3_HTML.jpg[/IMG]​

Figure 3
Alignment of an egg. Rounded part (A), Pointed part (B), Maximum width points (C and D), Focal Points (F1 and F2), Cross Point (E).
Shape Index can vary between 0 and 1.



*** Based on my findings so far though I would have to say it's not the most accurate. I did not read this article first to know this much detail about choosing. I may have had better results if I did. Maybe.

 

[eLiV8t]

So far, these chicks are of mix breed and from up to 3 hens.
When I got my now adult chickens there were 5 from someone that hatched eggs that she ordered. They are a silkie mix.

Although they didn't turn out with silkie type fathers there was one way they had a sex link to determine them. I wasn't sure till they matured but out of 5 there were 2 Cockrell.

The difference between them was the color of their skin. Silkies are known to have black skin and meat (I believe, correct me if I'm wrong. My memory gets hazy) but the chicks I had 3 are black (the females) and 2 are white skined (males, Cockrell). I assume there were multiple hens that layed this group of eggs.
When I started this experiment I was hoping for those kind of results even though I know sex links are only for the first generation.

They look to be a speckled olive egger, an olive egger and the 3rd lays a pinkish brown egg. They've all had a lavender hue to their feathers and eggs. Only the red Cockrell is father of the new chicks.

 

[eLiV8t]

Well I'm finding the same results. Of the 5 eggs hatched, the first 2 darker chicks are males. Based on them mounting the other hens. No one is crowing yet.

Im thinking that the darker colored silkie is a male also based on it having a comb with possibly 2 silkie hens.

I just love this red one. It looks like a polish.

Has anyone tried to pick out certain eggs in order to get more or only pullets (hens or females)?

I'm testing this out.
I pulled out the eggs that looked pointed and kept the roundest eggs under my broody hen.
They started hatching yesterday and I hope this experiment works. Have you tried this?
How did it turn out?

 

[eLiV8t]

The red one